1. Field of the Invention
The present invention relates to an ink-jet recording head using an ink jet recording system, and a method for manufacturing the ink jet recording head.
2. Description of the Related Art
As a method for manufacturing an ink jet recording head, conventional technique mentioned below is known.
A mold (male type) for an ink channel (path) is formed on a substrate by using a resist having solubility. Then, the mold is coated by a resin. Thereafter, the resist is eluted. In this way, the ink channel is formed without carrying out cutting process (for example, see Japanese Patent Application Laid-Open (JP-A) No. 5-330066, FIG. 7; and JP-A No. 6-286149, FIG. 5).
Concretely, after forming an ink supplying opening 208 on a substrate 201 on which heating resistors 202 are formed, a mold (male type) for an ink channel is formed on the substrate 201 by using a resist 203 having solubility (see FIG. 10A).
After a resin 205 is coated on the resist 203, patterning is carried out by a resist 204 on the resin 205 (see FIG. 10B).
Etching is carried out for the resist 205 with the resist 204 being used a mask to form ink discharge sections 206. Thereafter, the resist 203 having solubility is flown out (eluted). Thus, the ink channel 209 is formed (see FIG. 10C).
However, in a case in which the resin 205 is formed, with a single layer, on the whole surface of the substrate 201 at which the mold for the ink channel 209 is formed by the resist 203, a region other than the mold for the ink channel 209 is covered by the resin 205 of thick thickness, in order to make thickness of a region at which the ink discharge sections 206 are formed and is positioned above the ink channel 209, to be a desired thickness. In such a case in which the whole substrate 201 is covered by the thick resin 205, when the substrate is subject to heat treatment, stress is generated within the resin 205 due to difference between coefficients of thermal expansions of the substrate 201 and the resin 205 covering the substrate 201. This causes cracking in the resin.
The thicker a thickness of the resin is and/or the wider an area of the covering region of the resin is, the larger the stress generated within the resin becomes. Accordingly, in order to prevent cracking, it is necessary to reduce the stress by limiting a region on the substrate, where the resin covers, or by limiting a region on the substrate, where the resin covers with thick thickness.